Process of refining hydrocarbon oils with iron salts



A. LACHMAN Oct. 6, 1931.

PROCESS OF REFINING HYDROCARBON OILS WITH IRON SALTS Original Filed May8, 1929 & v v 0 6 INVENTOR 5977/01? /VCAMH/V- ATTORNEY known in commonuse.

Patented Oct. 6, 1931 UNITED. STATES, PATENT OFFICE ARTHUR LACIEMAN, OFIBERIKEIIE Y, CALIFORNIA, ASSIGNOR TO RICHFIELD OIL COM- PM 01?CALIFORNIA, WARE OF LOS ANGELES, CALIFORNIA, A CORPORATION OF DELA-PROCESS OF REFININ'G HYDROGARBON OILS WITH IRON SALTS Originalapplication filed May 8, 1929, Serial No. 361,513.

Divided and this application filed May 8,

1929. 'Serial No. 361,517.

This invention relates to a process of purifying and refininghydrocarbon oils obtained by distillation or cracking of mineral oils,such as lubricating oils, lamp oils, gasoline stocks or distillatesderived from oil shale. This application is a division of my applicationfor process of refining h drocarbon oils, executed April 20, 1929, erialN 0; 361,513, filed May 8, 1929, which consists of a similar method orprocess for purifying and refining mineral oil products with solublemetal salts.

.The process of refining hydrocarbon oils, as described in thisapplication, is applicable to all mineral oil products derived bydistillation or cracking operations, such as lubrieatingoils, lamp oilstocks, gasoline stocks, distillates derived from oil shale, etc., andis particularly ada table to gasoline stocks obtained by cracking higherboiling hydrocarbon oils. For the purpose of simplifying thedescription,reference will be made to gasoline only. i

Crude gasoline stocks obtained'by distilling or cracking petroleum oilsconsist of a mixture of saturated and unsaturated hydrocarbons togetherwith sulphur compounds, nitrogen bases and other substances of anundefined nature. These latter substances are readily oxidizable atordinary temperatures and are usually responsible "for the change ofcolor which takes place when refined gasoline is stored. Theseoxidizable substances are removed with diiiiculty when gasoline stocksare treated by the methods In order to show the nature of my inven tion,it is desirable to describe the method now in common use in 011refineries, andparticularly that step of refining gasoline stocks whichconsists in deodorizing and stabilizing the same. Crude gasoline stocksobtained by distillation of crude petroleum oil or by crackring a higherboiling petroleum oil, are customarily treated with approximately from 1per cent to as high as 8 per cent by weight sulphuric acid, the quantityof sulphuric acid depending upon the nature of the gasoline stock to betreated and the product desired. This acid treatment usually consists incommingling the gasoline stock with the required amount of sulphuricacid necessary to obtain the desired extraction, either by the wellknownbatch or continuous treatment, after which the products of the acidreaction are permitted to settle and then withdraw from the treatedgasoline stock. The acid treated gasoline stock is then neutralized bywashing with a water solution of an alkali and finally with water. Thistreatment removes most of the impurities, but subsequent treatments areusually necessary to deodorize and remove or convert corrosive sulphurcompounds into non-corrosive bodies. For this purpose, a water solutionof sodium plumbite or sodium hypochlorite is usually employed to renderthe gasoline sweet to the doctor test.

The general objections to a treatment of this character are asfollows:

(1) Gasoline purified by this method frequently becomes discolored whenstored for a period of time;

(2) Considerable quantities of sulphuric acid are required, which arediflicult to recover;

*1?) As high as 10 per cent of the valuable sta le unsaturatedhydrocarbons contained in the gasoline stock may be'lost; and

(4) The treatment must frequently be followed by a deodorizing orsweetening process, such as that heretofore described;

Now, I have discovered that the sulphuric acid normally used to treatcrude gasoline stocks may be reduced to a cat extent, and in many casesmay-be entire y eliminated by the employment of a water solution ofcertain metallic salts, or mixtures of the same, which may be zinc,copper, cadmium, mercury, iron, chromium, manganese, aluminum, nickel orcobalt water soluble salts, such as tion will now passing the solutionof any of the the chloride, bromide, iodide, sulphate, nitrate, and alsoany of the Water soluble salts of the above named metals of organicacids, such as the sulphonic acids of benzol, toluol and xylol, or thesulphonic acids derived from the treatment of petroleum oils withsulphuric acid.

The process described briefly consists in hydrocarbon oil product suchas gasoline stock while in a vapor state, through or in contact with a.hot concentrated water aforesaid metallic salts or mixtures thereof. Thegasoline stock so treated is usually pure enough for immediate use,although it sometimes may contain small amounts of hydrogen sulphide,which may be removed by washing with an alkaline solution of sodium orcalcium hydroxide, or the carbonates of sodium or potassium.

The hydrocarbon oil stock to be treated by my invention may or may nothave had a preliminary treatment with st lphuric acid, or other agentsto partly punfy the same, or may be first partly purified by myinvention and the purifications completed by methods known in the artsuch as treatment with caustic alkali, sulphuric acid, etc. In case ofgasoline stocks produced'by cracking high sulphur bearing crudepetroleum oils or residuums, it may be advantageous to treat suchgasoline stocks with small amounts of sulphuric acid before thetreatment with a concentrated water solution of any of the afore-statedmetallic salts, which may also be followed by treatment with an alkalinewater solution of sodium, potassium or calcium hydroxide, or thecarbonates or sodium or potassium.

Although a solution of less concentration may be employed which mayrange from 50 or less to approximately per cent, the strength of thewater solution of the metallic salt or mixture of salts employed ispreferably a substantially concentrated solution, and the temperatureemployed for the treat ment is approximately 300 to 400 degrees F.,which normally fluctuates, depending upon the vaporizing temperature ofthe oil under treatment.

lVith the foregoing preliminary explanation, the preferred embodiment ofmy invenbemore fully explained by reference to the accompanying drawingwhich is a diagrammatic view of one form of apparatus which maybeemployed for carrying out the objects of the present invention.

Referring to the drawing, 2 indicates a pipe leading to "a pors notshown, such as a fractionating tower. employed to separate lower boilingoils from higher boiling oils. B indicates a tower of suitable heightand diameter filled with resistant or contact material, such as firebrick,

spiral tile or the like, indicated at 3, which forms numerous tortuouspassages through source of crude gasoline vathe tower, although it is tobe understood that the well-known bubble cap contact tower may beemployed. Disposed above the tower or adjacent to the same, is a tank 12containing a substantially concentrated water solution of a metallicsalt or mixtures of the same, as heretofore enumerated, having aconcentration of from 50 per cent or less to as high as approximately 85per cent. This tank is connected to the top of the tower by means of apipe 4 having a regulating valve 5. Thispipe terminates over a spreaderplate 6 and this plate evenly distributes the water solution of themetallic salt or salts when the valve 5 is opened, over the brick workor contact material. The water solution of the metallic salt or saltsflows downward through this contact material and may finally bedischarged through the bottom by a pipe 7,

after which it is treated for recovery. The tower B is also providedwith a steam or water inlet pipe 8, which intermittently or continuouslysupplies a predetermined amount of water or steam to the tower. The hotgasoline vapors from the pipe 2 enter the lower end of the tower B at apoint 9. The oil vapors pass up through the numerous contact passages inthe brick work and thereby come into intimate contact with the saidwater solution of metallic salt or salts flowing over the same. Althoughother temperatures may be employed, both the water solution of metallicsalt or salts and oil vapors are generally maintained at a temperatureof approximately 300 toAOO degrees F., and the oil vapors are dischargedat the upper end of the tower through a pipe 10 which 1s connected-witha condenser 11 of suitable construction. The gasoline vapors passingthrough the contact tower B at the temperature specified, vaporize acertain amount of water from the water solution of metallic salts andthe purpose of the steam or Water inlet pipe 8 is that of continuouslymaintaining the solution at a certain water content so as to maintainthe necessary fluidity which is essential for good contact between therising gasoline vapor and the down-flowing water solution of metallicsalt or salts. Preferably the concentration of the water solution ofmetallic salt or salts is maintained at its predetermined limits ofconcentration by a continuous introduction of water or water vapor."Otherwise solid metallic salt or salts and solid sludge impurities mayplug the passages through which the gasoline vaors are being conducted.

While not always necessary, it is beneficial that the water solutionsalts contain hydroxides or oxides of any of the metals, or mixturesthereof, heretofore enumerated, before being introduced into the system.This may be accomplished by agitating the water solution of the metallicsalt or salts with any of the hydroxides or oxides wherein a water ofany of the enumerated metals. The optimum amount of the metal oxide orhydroxide ranges from about of 1 per cent to 3 per cent by weight of thewater'solution of metallic salt or salts. In explanation, when the 1oxides or hydroxides of any of the aforementioned metals or mixturesthereof are soluble in substantial amounts in the salt or salts solutionat the temperature and pressure employed, it is no doubt that thebeneficial action will be enhanced, but even if no substantialsolubility exists, useful effects can be obtained if the oxides andhydroxides are suspended in the salt or salts solution.

The reaction tower B is kept full of the Water solution of the metallicsalt or salts containing metallic hydroxides or oxides such as zinchydroxide, and a fresh supply of approximately 15 pounds of the saidsolution is admitted for each barrel of gasoline stock under treatmentand a corresponding amount of the spent solution is withdrawn at thesame time.

The amount of Water vapor required to replace the vaporized water fromthe water solution of metallic salt or salts varies Within wide limits,depending upon the concentration of the solution employed, thetemperature at which the operation is carried out and the nature andamount of inert gases which may accompany the gasoline vapor beingtreated. By this treatment the major portion of the impurities containedby the gasoline stock is removed and carried out with the Water solutionof metallic salt or salts as a sludge and the purified gasoline vapors,when condensed, are suitable for use as a refined gasoline stock of highpurity.

While the process herein described is well adapted for carrying out theobjects of the present invention, it is to be understood that variousmodificationsv and changes-may be made without departing from theinvention, such for example as the use of centrifugal or othermechanical mixers or the employment of any of the well-known contacttowers solution of a metallic salt or mixtures of metallic salts, eitherorganic or inorganic, heretofore enumerated, may be commingled with orbrought into contact with a petroleum oil vapor at the reactingtemperatures and the invention includes all such modifications andchanges as come within the scope of the appended claims.

What I claim is:

1. A process of refining mineral oils, com prising, vaporizing a mineraloil, contacting the vaporized oil with a maintained water solution of aniron salt, and then condensing purified oil vapor separated fromproducts of reaction and treating agent. I

2. A process of refining mineral oils. comprising, vaporizing a mineraloil by the application of heat, contacting the heated vaporized mineraloil with a substantially concentrated water solution of an iron salt,maintained in solution, and then condensing purified oil vapor separatedfrom products of reaction and treating agent.

3. A process of refining mineral oils, comprising vaporizing a mineraloil, contacting the vaporized mineral oil with a maintained watersolution of a mixture of iron salts, and densing purified oil vapor,separated from products'of reaction and treating agent.

4. A process of refining mineral oils, comprising, vaporizing a mineraloil by the application of heat, contacting the heated vaporized mineraloil with a maintained water solution of an iron salt, and thencondensing purified oil vapor separated from products of reaction andtreating agent.

5. A process of refining mineral oils, com prising, vaporizing a mineraloil by the application of heat, contacting the heated vaporized mineraloil with a maintained water solution of an iron salt heated to atemperature of not less than the vaporizing temperature of the vaporizedmineral oil under treatment, and then condensing puri fied oil vaporseparated from products of reaction and treating agent.

6. A process of refining mineral oils, comprising, heating a mineral oilto form a vapor, at temperatures of approximately 300 to 400 degrees F.,contacting the heated vapor with a water solution of an iron saltmaintained in solution at a substantially similar temperature, and thencondensing purified oil vapor separated from products of reaction andtreating agent.

A process of refining mineral oils, comprising, heating a mineral oil toform a vapor, at temperatures of approximately 300 to 400 degrees F.,passing the heated vapor through or in contact with a water solution ofiron salts maintained in solution at a substantially similar temperatureand having a concentration of approximately 85% and then condensingpurified oil vapor separated from products of reaction and treatingagent.

8. A process of refining mineral oils, comprising, heating a mineral oilto form a vapor, contacting the heated vapor with a maintained watersolution of iron salts, containin iron hydroxide, and then condensingpuri ed oil vapor separated from products of reaction and treatingagent.

9. A prising, heating a mineral oil to form a vapor, passing the heatedvapor through and in contact with a water solution of iron salts,maintaining the solution in a fluid condition by the addition of waterduring contact of the vapor and treating solution and condensingthevapor after passing through the solution.

10. A process of refining mineral oils, comprising. commingling thevapors of a mineral oil with a water solution of an iron salt maintainedin a fluid condition during contact of process of refining mineral oils,comthe vaporized oil with a water por, passing the vapor through and incontact with a water solution of an iron salt containing iron oxide,intermittently introducing water into the solution of iron salt tomaintain the aqueous solution containing iron oxide and continuouslycondensing the vapor oi: the purified mineral oil separated from thesolution of iron salt containing iron oxide and products of reaction.

\ In testimony whereof I aflix my signature.

ARTHUR LACHMAN.

the vapors and treating solution and then condensing purified oil vaporseparated from products or" reaction and treating agent.

11. A process of refining mineral oils, comprising, heating a mineraloil to form a vapor, passing the heated vapor through and 111 contactwith a water solution of an iron salt containing iron hydroxide,maintaining the solution in a fluid condition by the addition of waterduring contact of the vapor and treating solution and condensing thevapor after passing through the solution.

12. A process of refining mineral oils, comprising, heating a mineraloil to form a vapor, passing the heated vapor through and in contactwith a water solution of iron salts, containing from of 1 per cent to 8per cent by weight of iron hydroxides and oxides, maintaining thesolution in a fluid condition by the addition of water during contact ofthe vapor and treating solution, and condensing the vapor after passingthrough the solution.

13. A process of refining mineral oils, comprising, heating a mineraloil to form a vapor, passing the heated vapor through and in contactwith a Water solution of iron salts, maintaining the concentration ofthe solution within predetermined limits by the addition I, of waterduring contact of the vapor an treating solution, and condensing thevapor after passing through the solution.

14. A process of refining mineral oils, comprising, heating a mineraloil to form a vapor, at temperatures of approximately 300 to 400 degreesF., passing the heated vapors through and in contact with a Watersolution of an iron salt maintained at a similar temperature and havinga concentration of approximately -85%, maintaining the concentration ofthe solution as Specified, by the continuous addition of water duringcontact of the vapor and treating solution and then condensing thevapor. after passing through the solution.

15. A process of refining mineral oils, comprising, vaporizing a mineraloil, contacting solution of an iron salt, intermittently introducingwater into the solution of iron salt to'maintain the aqueous solutionand continuously condensing vapors of the purified mineral oil separatedfrom the products of reaction and solution of iron salt. I 1

16. A process of refining mineral oils, comprising, heating a mineraloil to form a vapor, passing the vapor through and in contact with awater solution of iron salts contain-. ing iron hydroxide,intermittently introducing water into the solution of iron salts tomaintain the aqueous solution containing iron hydroxide "andcontinuously condensing the vapors of the purified mineral oil separatedfrom the products of reaction andsolution of iron salts containing ironhydroxide.

17 A. process of refining mineral oils, coinprising, heating a mineraloil to form a va

